Technical Field
The invention relates to a fire protection device for small electrical devices having housings. It also relates to a small electrical device with a housing that is equipped with such a fire protection device. Finally, it relates to the use of a bursting capsule as a fire protection device for small electrical devices.
Background Information
Small electrical devices for the purposes of this invention are devices with small dimensions that operate using electric power, wherein small dimensions are understood to mean edges that are a maximum of 1 m in length, typically in a range of several cm to several dm. For example, a typical small electrical device is a power adaptor as is often currently used in conjunction with laptop computers. These kinds of power adaptors have dimensions of 10 cm to 15 cm along its longest edge length and up to 10 cm along its shortest edge length. Encapsulated in a housing, they contain electrical components for the voltage conversion of a supply voltage originating from the mains voltage, for example 230V AC in Europe, into a supply voltage for the electrical device being supplied, for example a laptop, e.g. a DC voltage of 12 V.
These kinds of small electrical devices, for example such power adaptors, heat up during operation. If there is any damage, this kind of small electrical device, such as a power adaptor, can overheat, for example as a result of a short circuit or an overload that is not adequately absorbed by a corresponding safety device, which under unfavorable circumstances can lead to the plastic components in the small electrical device catching fire, and can thereby lead to a fire. Various house and apartment fires, or fires in office buildings, are caused by defective electrical devices that catch fire as a result of such malfunctions.
Although such small electrical devices are frequently equipped with electrical fuses that are tripped in the event of a defect and a resulting overcurrent, and that are supposed to cut the power supply, such fuses are not always adequate protection against a fire in this kind of small electrical device. In particular, such fuses can no longer provide effective protection if excessive overheating of the small electrical device, or of the electrical components in the small electrical device, has already occurred before the fuse is tripped.